Sonny Bill Williams intimated that he would probably have stayed in rugby union with the Chiefs had he known he would adapt to the game as easily as he has.

Williams yesterday announced he would be moving to Japan with the Wild Knights at the end of the Super Rugby campaign and then on to league (thought to be with the Sydney Roosters) following that five-month stint in a deal which includes the opportunity to fight one boxing bout during that time, reportedly in South Africa..

He had agreed a return to league upon his departure to Toulon in 2008 and this move has honoured that agreement. However, the World Cup winning midfielder said he would return to the Chiefs ‘Even if there was no money here I’d come and play for free’ and continued by seemingly showing regret at the deal.

‘I didn’t think I would have loved it as much as I have back here. To be honest I kind of felt like I’d found my place at the Chiefs, with the boys, but it just goes back to [the fact] I’ve given someone my word, this was a while ago, and I’ve had to go on with it even though it was tough,’ he said.

Williams said that at the time he made the commitment to league he was not confident he could return to New Zealand and make a success of rugby.

‘I might not have been good enough and pressure was certainly on me, it wasn’t on anyone else. If it was about the money then I would have just stayed in France [with the Toulon rugby club] where I was getting pretty good coin.’

Williams is available to play in the first two Tests of the Rugby Championship but will not be selected as the selectors feel it makes more sense to go with a player who can establish himself.